This report highlights actions that can be pursued today and lessons learned in different countries on implementing energy efficiency policies for the building sector. The publication provides a detailed overview of the key technologies that are needed to decrease growth in buildings energy demand. Examples of best available building technologies combined with renewable energy sources in advanced buildings only represent a small niche market today. New construction under much more stringent building codes is needed in order to achieve energy neutrality in new buildings. Besides, the process of deep renovation using whole-building integrated solutions need to be accelerated.